题目链接:https://www.luogu.org/problemnew/show/P2919 1.搜索的时候分清楚全局变量和局部变量的区别 2.排序优化搜索 #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; const int maxn = 2000; const int inf = 0x7fffffff;…

P2919 [USACO08NOV]守护农场Guarding the Farm 相似题:P3456 [POI2007]GRZ-Ridges and Valleys 按海拔是否相同分块 每次bfs海拔相同的块,根据与周围的块的大小关系判断是否是山丘. #include<iostream> #include<cstdio> #include<cstring> #include<queue> #include<cctype> #define re re…

P2919 [USACO08NOV]守护农场Guarding the Farm 题目描述 The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows. He wonders how many guards he will need if he wishes to put one on top of each hill…

https://www.luogu.org/problem/show?pid=2919 题目描述 The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows. He wonders how many guards he will need if he wishes to put one on top of each…

题目描述 The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk-cows. He wonders how many guards he will need if he wishes to put one on top of each hill. He has a map supplied as a matrix of i…

链接:P2919 ----------------------------------- 一道非常暴力的搜索题 ----------------------------------- 注意的是,我们要从高出往低处搜,所以要sort一边 然后没有什么值得成为绿题的部分了 绝对是恶评 ----------------------------------- 题面有歧义,我们在搜索的时侯扩展的条件是<=,不是等于 ----------------------------------- #include…

题目 1619: [Usaco2008 Nov]Guarding the Farm 保卫牧场 Time Limit: 5 Sec  Memory Limit: 64 MB Submit: 491  Solved: 218 [Submit][Status] Description The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable…

1619: [Usaco2008 Nov]Guarding the Farm 保卫牧场 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 498  Solved: 223[Submit][Status] Description The farm has many hills upon which Farmer John would like to place guards to ensure the safety of his valuable milk…

P3079 [USACO13MAR]农场的画Farm Painting 题目描述 After several harsh winters, Farmer John has decided it is time to re-paint his farm. The farm consists of N fenced enclosures (1 <= N <= 50,000), each of which can be described by a rectangle in the 2D plane…

基环树森林,然而我比较菜,直接tarjan找环. 发现缩点之后变成了DAG,每一个点往下走一定会走到一个环,缩点之后搜一遍看看会走到哪个环以及那个环的编号是多少,答案就是环的$siz$$ + $要走的路程. 比较垃圾的我忘记了判重边WA了好多发…… 时间复杂度$O(n)$. Code: #include <cstdio> #include <cstring> using namespace std; ; << ; , dfn[N], low[N], cur[N]; ,…